Fisheye lenses are super-wide angle lenses that add some fun to photos. They add curves to straight lings to give a new perspective to normal shots. Notice that the horizontal and vertical lines are curved in the example photo. A zoom fisheye lens has a variable focal length as does any zoom lens, but it has the appearance of changing the "fisheye" affect. Very short focal lengths add strong curvature to straight lines, while longer focal lengths produce a more subtle curvature affect. Rent a fisheye camera lens with your next order to add some variety to your shoot.